1. Field of the Invention
This invention relates to cargo support systems and, more particularly, to a system for maintaining cargo in an elevated position relative to a floor surface in a storage space in over-the-road vehicles.
2. Background Art
The freight hauling industry has become increasingly competitive. Higher fuel costs have reduced margins. To remain competitive, entities are required to maximize utilization of cargo storage space in over-the-road vehicles, such as semi-trailers.
The assignee herein has developed cargo storage systems for such vehicles which allow more complete utilization of the upper volume of storage spaces which commonly is not occupied by cargo that is stacked from the floor upwards. The assignee herein offers, among other options, a system which it identifies as its Lift-A-Deck™ system. The Lift-A-Deck™ system utilizes vertically extending logistic tracks that are secured to facing side walls on such trailers. The tracks have a low profile so as not to occupy any significant volume of the usable storage space. Beams span between the tracks and may directly support cargo or panels upon which cargo can be placed. The tracks permit releasable connection of the beams at different heights that are selected based upon the configuration of the cargo.
With most trailers, these tracks can be integrated into the side walls of the trailer by using a series of fasteners that secure the tracks to framework in the side walls at spaced intervals from the floor to the roof of the vehicle. These fasteners will typically be directed through panels bounding the storage space and into reinforcing posts and other framework within the panels or to which the panels are secured.
While the same need for these elevated cargo supports exists in trailers that have a heated or cooled internal environment, modification of these conventionally constructed trailers to provide elevated supplemental cargo support surfaces presents problems, particularly with respect to mounting the tracks that support the spanning beams. These trailers are commonly constructed with insulated panels that have an insulating material between encasing layers or skins. These panels may extend substantially the full height of the storage space. These panels may lack a rigid structural framework that will support fasteners to positively secure the beam supporting tracks in a securely fixed position.
Incorporating framework into these panels during initial manufacture detrimentally changes their insulating properties such as R value, thereby decreasing efficiency of operation.
Insulating properties might also be compromised by directing fasteners into the panels without adequate internal structural framework. This may additionally compromise the overall integrity of these panels, which could lead to shifting or, in a worst case, release of the supplemental supporting structure. Penetration of these panels by fasteners may also make them prone to the detrimental ingress of environmental moisture, which may be absorbed by the insulating material.
Since the majority of the area of the insulated panels is not equipped to support penetrating fasteners, the only practical method of supporting beams in existing trailer units to this point has been to provide an independent framework that is primarily self-supporting. The vertical beam support components would thus be required to project into the storage volume, taking up valuable space that could otherwise be used to accommodate cargo.
While a need for supplemental, elevated cargo support in refrigerated trailers has existed, the industry has not devised a practical design that is commercially feasible in terms of being structurally sound while at the same time not taking up any appreciable amount of usable cargo space. The ability to retrofit existing cargo units with conditioned internal environments has particular value but, to date, has not been practically achievable.